Yeah he did give up on it after twenty years of heavy usage.
I watched an episode Of Bill Mahar today and he had a 76 year old comedian guest, the guy was a flaming fag but he told a story about how he talked a friend into doing it recently with him for the first time, and said he didn't recommend it for kids but said it was a great experience and recommends all seniors to try it.
Based on my experience, it's not something you would want to do every day but if you are healthy you should give it a try. It may seem hard on your body while you are tripping (a mental effect) but it really has few effects in that regard and no matter how much you take it's almost impossible to od, you would have to take oz's of the stuff. Or at least grams. You can't eat enough hits to do it.